Finite Element Model for Cohesive Sediment Transport

A mathematical model that simulates erosion, transport and deposition of cohesive sediments in a two-dimensional flow field is presented. The governing equations are solved by the finite element method using the Galerkin formulation. The domain is subdivided into a series of triangular elements in which a quadratic approximation is made for the suspended sediment concentration. Expressions used for the rate and conditions under which erosion and deposition occur are from previous experimental studies. Continuing aggregation is accounted for by specifying the settling velocity of the flocs in each element. The model is verified by comparison with analytic solutions and the results of a flume test.